1. Field of the Invention
The present invention relates to an electronic equipment using a fuel cell as a power supply. In particular, the present invention relates to a small electronic equipment which uses, as a power supply, a fuel cell with a power generation of several milliwatts to several hundred watts, which can be carried around, and which allows a user to hold the equipment with his/her hand for use. Examples of the small electronic equipment include digital cameras, digital video cameras, small projectors, small printers, notebook computers, personal digital assistants (PDAs), and mobile telephones.
2. Description of the Related Art
Up to now, a lithium ion battery, a nickel manganese battery, an alkaline dry battery, or the like is often used as a power supply of a portable electronic equipment. Such a battery generates electric power through chemical reaction inside the battery. This is because the battery is often mounted in a battery chamber which is relatively hermetically sealed inside the portable electronic equipment. Further, functions of the electronic equipment are becoming more sophisticated and the electronic equipment is becoming more multifunctional, so a necessary amount of electricity is accordingly increasing. On the other hand, downsizing of the electronic equipment has been intended in terms of outer dimension. Density of capacitance of the above-mentioned various batteries does not necessarily materialize required improved performance of the electronic equipment.
Thus, an electronic equipment using a fuel cell as its power supply has emerged. However, since a fuel cell uses oxygen in the air to generate electric power, which is different from a conventional battery, an opening portion, which does not exist in a conventional portable electronic equipment, is necessary for making the battery chamber communicate with an outer surface of a casing of the electronic equipment.
Meanwhile, Japanese Patent Application Laid-Open No. 2005-017327 proposes an electronic equipment which utilizes a fuel cell as a power supply. The electronic equipment disclosed in Japanese Patent Application Laid-Open No. 2005-017327 is described with reference to FIG. 7. By providing an air hole 15 for making a battery chamber 18 provided in an electronic equipment 1 communicate with the outside of a casing in a portion of the electronic equipment 1 away from a portion held by a user, it is attempted to supply without fail oxygen to a fuel cell in the battery chamber 18. The electronic equipment in FIG. 7 additionally includes a release button 11, a light-emitting unit 12, a finder 13, and a lens barrel 14. An air-orifice guard 16, lid 17 and front cover 19 are also displayed.
However, provision of the air hole for communication with the fuel cell in a portion away from a portion held by a user as in JP 2005-17327 is a factor against downsizing of the electronic equipment which is required to utilize its outer surface portion as effectively as possible.